Adoption of the MASS Code – what does it mean in practice? 

New regulations rarely change the world on the day they enter into force. They change it when lawyers, shipowners and insurers start asking the right questions – preferably before those questions become the subject of a dispute. The MASS Code is precisely that kind of regulation, and that kind of list of questions. 

The International Maritime Organization has taken an important step towards regulating autonomous shipping. During the 111th session of the IMO Maritime Safety Committee, the International Code of Safety for Maritime Autonomous Surface Ships, or the MASS Code, was adopted. It is the first global regulatory framework for ships using autonomous or remotely controlled functions. 

From 1 July 2026, the Code is intended to be non-mandatory. It is designed to help shipowners, shipyards, technology providers, insurers and operators prepare for future mandatory rules. According to the timetable, the mandatory version of the Code is to be adopted on 1 July 2030 and enter into force on 1 January 2032. 

What does the MASS Code cover? 

The MASS Code applies to cargo ships covered by Chapter I of the SOLAS Convention which use systems enabling certain functions to be performed autonomously or remotely. The Code also covers the associated remote operations centres, or ROCs. 

It has been developed as a “goal-based code”. This means that it does not impose detailed technical solutions or specific technologies that must be used on board. Instead, it sets out safety goals and functional requirements that should be met. 

This approach is particularly important in the rapidly developing automation sector. Detailed technical regulations could very quickly become outdated. 

The MASS Code and existing regulations 

The MASS Code does not replace existing IMO conventions. Autonomous ships will still have to comply with the requirements arising, among others, from the SOLAS Convention and other applicable international instruments. 

The Code is supplementary in nature. Its purpose is to fill the gaps that arise where existing regulations assume the presence of crew on board, while the ship performs some functions autonomously or remotely. 

Humans at the centre of the system 

One of the most important assumptions is the emphasis on the so-called human element. The Code provides that every MASS must have a master responsible for the ship. This also applies where the master is not physically present on board. 

Persons responsible for the operation of the ship must have a real ability to supervise autonomous systems. This means that they should be able to: 

• understand the information provided by the systems,
• monitor their operation,
• assess the decisions made by the system,
• take control when necessary,
• correct or override the system’s operation. 

Remote Operation Centres – ROCs 

One of the most important new elements introduced by the MASS Code is the regulation of remote operations centres, or ROCs. These are shore-based centres from which ship functions can be monitored or operated. 

The Code treats an ROC as an integral part of the safety system. It provides for: 

• certification of the ROC for a specific ship,
• definition of the ROC’s operational limitations,
• assessment of communication between the ship and the ROC,
• safety management procedures,
• personnel requirements,
• inclusion of the ROC in the safety management system,
• protection against cyber risks. 

Design and description of operation 

One of the documents required under the MASS Code is the Concept of Operations, or ConOps. It shows how the ship is intended to operate in practice. This is not only a description of the technology, but also a description of the operation, the people involved, the procedures, the limitations, and the relationships between the ship, the autonomous systems and the remote operations centre. 

Two important concepts are linked to ConOps: 

1. Operational Envelope (OE) – the range of conditions in which the ship as a whole can operate safely,
2. Operational Design Domain (ODD) – the conditions for the safe operation of individual autonomous systems. 

It can be expected that, in future collisions, one of the key questions will be whether the ship and its systems were operating within the approved OE and ODD. 

From a legal perspective, these concepts will be of fundamental importance in future disputes. The question of whether the ship was operating within its approved operational scope is likely to become a standard starting point for analysing liability, both in compensation proceedings and in relations with insurers. 

Risk management 

The Code relies heavily on risk analysis. Every autonomous ship project will require a detailed identification of hazards, as well as demonstration that the safety measures applied are sufficient to keep the level of risk within acceptable limits. 

The analysis should cover, among other things: 

• equipment and software failures,
• loss of connectivity,
• human error,
• cyber risks,
• fires and explosions,
• adverse weather conditions,
• emergency situations related to vessel traffic. 

For the industry, this means that technical documentation, logs, procedures, tests and audits will become more important. These are the elements that will show whether the system was safe not only on paper, but also in practice. 

Fallback state 

One of the most distinctive concepts in the MASS Code is the so-called fallback state, meaning a pre-designed and tested emergency state. 

If a ship moves outside its approved safe operating range, or if its systems fail, it should automatically enter a state that minimises the risk to people, other ships and infrastructure. 

Such actions may include reducing speed, transferring control to a remote operator, or carrying out other pre-programmed safety procedures. 

The IMO requires such mechanisms to be provided for already at the design stage and to be subject to tests confirming their effectiveness. 

For entities entering transactions and contracts in the maritime sector, it is already important to take fallback state mechanisms into account in agreements with autonomous system manufacturers and in contractual liability clauses. 

Cybersecurity as an element of maritime safety 

The growing reliance on software, satellite communications and remote control also means increased exposure to digital threats. 

For this reason, the MASS Code devotes particular attention to cybersecurity. Both the ship and the ROC must be protected against unauthorised access, data manipulation, takeover of control or disruption of communications. 

This may also have significant consequences for the insurance market, where the importance of specialist policies covering cyber risks is likely to increase. 

What next 

The current version of the Code is non-mandatory. The IMO intends to use the coming years to gather experience from its practical application. 

In 2028, the IMO plans to begin work on the mandatory version of the MASS Code. It will be based on experience gathered during the non-mandatory phase. At the same time, amendments to SOLAS are to be considered so that the mandatory Code can be incorporated into the system of international law. 

Companies that start analysing their contracts, policies and liability structures in the light of the MASS Code now – rather than only in 2030 – will be in a much better position once the regulations become mandatory. These companies will also be able to submit comments on an ongoing basis and help shape the emerging system. 

Summary 

The MASS Code is the first common point of reference for states, shipowners, shipyards, ROC operators, system manufacturers and insurers. It shows that autonomy in shipping will not be assessed solely by whether a ship can perform a manoeuvre without a human on board. 

What will matter is the whole system: the way the ship is designed, the division of tasks between humans and technology, the quality of communications, documentation, risk analysis, cybersecurity and preparedness for emergency situations.